1. Field of the Invention
The present invention relates to a machine translation apparatus which can distinguish whether the input word string is a normal sentence or a special words string, such as a heading or an itemized sentence which begin with a number, and appropriately translate the word string according to its style.
2. Description of the Prior Art
A machine translation apparatus as is known from the prior art is described as follows. Such a machine translation apparatus inputs the source language text entered from a keyboard into a translation module as controlled by the main CPU, and the input source text is translated into the target language using dictionaries, grammatical rules, and tree structure conversion rules stored in the memory of the translation module.
When a special sentence, such as an itemized sentence which begins with a number is to be translated, manual removal of the lead number is required before translation by the translation machine or otherwise, the translation will fail.
When a translation is attempted using a machine translation apparatus according to the prior art as hereinbefore described, translation of itemized sentences which begin with a number will fail because the conventional machine translation apparatus is not able to determine whether the numeric expressing the aforementioned number is a cardinal number or ordinal number. For example, when the original English itemized sentence:
2. This is a book. PA1 Surface Temperatures Rise
is to be translated into Japanese, the translation analysis should begin not from the first occurring letter "2", but from the second occurring "This". It is therefore necessary for the operator to manually delete the numeric, thus increasing the burden on the operator.
Also, when a translation is attempted using a machine translation apparatus according to the prior art as heretofore described, because the structure of the original input sentence (for example, English sentence) is decided according to grammatical rules stored in memory, and it is not possible to distinguish whether the original being processed is a sentence or a heading (which are, in general, noun phrases), the grammatical rules for common sentences stored in the aforementioned memory are applied irrespective of whether the input original is a heading, and misinterpretation of the original often occurs. For example, when the original English word string of a heading:
is to be translated into Japanese, the translation analysis should properly decide whether the word "Rise" is a verb or a noun, because in Japanese, the verb form and the noun form of the word "Rise" are different. Furthermore, there has also been the problem that since the beginning of each word in a word string forming a heading is normally a majuscule, certain words in the heading may not match the registered words in the dictionary when the dictionary is referenced; as a result, said words may be handled as proper nouns or determined to be unlearned words, thereby making part of speech determination for said words difficult, and making it easier for misinterpretations to occur.